1CAN038604, Forwards Revised Schedule for Completion of Inadequate Core Cooling Sys Milestones (NUREG-0737,Item II.F.2).Two Changes to 830826 Conceptual Design Implemented Based on Further Evaluations & 821210, Order for Mod of License

Forwards Revised Schedule for Completion of Inadequate Core Cooling Sys Milestones (NUREG-0737,Item II.F.2).Two Changes to 830826 Conceptual Design Implemented Based on Further Evaluations & 821210, Order for Mod of License

ML20140E680
Person / Time
Site:	Arkansas Nuclear
Issue date:	03/18/1986
From:	Enos J ARKANSAS POWER & LIGHT CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM 1CAN038604, 1CAN38604, NUDOCS 8603280127
Download: ML20140E680 (5)

Text

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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK. ARKANSAS 72203 (501) 3714000 March 18, 1986 1CAN038604 Mr. J. F. Stolz, Director PWR Project Directorate No. 6 Division of PWR Licensing - B U. S. Nuclear Regulatory Commission Washington, DC 20555

SUBJECT:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 NUREG 0737 Item II.F.2 ANO-1 ICC Program Plan Changes / Milestone Schedule

Dear Mr. Stolz:

The purpose of this letter is to inform you of changes to the AN0-1 ICC program plan and to provide a schedule for the completion of the remaining ANO-1 ICC milestones.

Two changes to the NRC approved conceptual design for the ANO-1 ICC system have been made since our program plan submittal of August 26, 1983 (0CAN088314). These changes were made based on further evaluations of our conceptual design and'other designs which also meet the intent of the December 10, 1982 " Order for Modification of License."

The first change to our program plan involves the use of a AP measurement system for tracking hot leg level instead of the previously proposed Radcal Gamma Thermometer (RGT) stillwell design. The AP measurement system will consist of one wide-range monitor and four narrow-range monitors on each hot lea. A schematic of the proposed AP measurement system is presented as Figure 1.

The advantages of the AP system design over the RGT stillwell design are as follows:

1) The AP system affords redundancy in each hot leg level measurement (i.e., if the wide range monitor fails, the narrow range monitors still allow level measurement). A single RGT probe per hot leg was originally proposed.

2) The RGT stillwell design would require the installation of additional piping off the hot leg whereas the AP system requires the addition of hot leg taps.

8603280127 860318 q PDR ADOCK 05000313 P PDR 0r0, MEMBER MOOLE SOUTH ufrufsES System

March 18, 1986 The other change to the program plan involves the use of qualified Core Exit Thermocouples (CETs) for in-core monitoring instead of the previously proposed use of RGTs for this purpose. The newly proposed system consists of sixteen (16) qualified CETs (4 per core quadrant) to be installed during the ANO-1 seventh refueling outage (1R7) which is currently scheduled for ,

August 22 through October 31, 1986. This installation will meet the intent of the order. Eight (8) additional qualified CETs will be installed during the ANO-1 eighth refueling outage (1R8) which is currently scheduled for April through June,1988.

The reason for delaying installation of the eight (8) additional CETs until IR8 is to obtain full utilization of the existing in-core detectors. These detectors will not be fully depleted until 1R8. It is estimated that the unrecoverable cost of early replacement of these detectors would be approximately $80,000.

Technical Specifications covering the use of'ICC instrumentation (i.e., the CETs, the AP system and the Radcal vessel level probes) will be submitted following the installation of the additional CETs during 1R8. It is necessary that the additional CETs be installed prior to submitting Technical Specifications to provide assurance that an adequate number of CETs per core quadrant can be maintained operational. l The schedule for the completion of the remaining ANO-1 ICC milestones is presented as Attachment 1. The last schedule, presented in our letter of January 13, 1984 (ICANB18404), has been revised to incorporate the necessary additional time required to evaluate the proposed changes to the program plan and changes in outage dates.

Very truly ours, f/

J. Ted Enos, Manager Nuclear Engineering & Licensing JTE/MJS/sg l

ATTACHMENT 1 ANO-1 ICC MILESTONE SCHEDULE

1. Submit Final Design Description - The final design description for ICC instrumentation is currently scheduled to be submitted to the NRC by July 4, 1986. This revised milestone incorporates the necessary additional time required to evaluate the proposed changes to the program plan. This schedule allows for the inclusion of necessary information to ensure that this document reflects current design.

2. Submit Emergency Operating Procedure (EOP) technical guidelines - The E0P technical guidelines are to be revised to incorporate the ICC system. This revision is currently scheduled to be submitted to the NRC by July 4, 1986.

3. Complete installation of ICC instrumentation - Installation of 16 Core Exit Thermocouples (CETs), the Radcal Gamma Thermometer (RGT) vessel level probes and the hot leg AP system will be completed during 1R7 (currently scheduled for August 22 through November 1,1986).

4. Turn on system for operator training - The ICC system is currently scheduled to be available for operator training and familiarization after 1R7.

5. Complete ICC instrumentation functional testing and calibration -

Functional testing and calibration of the ICC system are scheduled to be completed 90 days after 1R7.

6. Submit Implementation Letter - The ICC system implementation letter is currently scheduled to be submitted to the NRC 180 days after completion of IR7.

7. Approve plant-specific installation and E0P technical guidelines - This milestone is based on NRC schedules.

8. Prepare revisions to plant operating procedures and emergency procedures and complete procedure walk-through - Revisions to plant operating procedures an1 emergency procedures to incorporate details of the use of the ICC system are to be completed after NRC approval of the plant-specific installation and the E0P technical guidelines.

Procedure walk-through will be done concurrent with procedure revision.

9. Implement modified operating procedures and emergency procedures - Full implementation of operating procedures and emergency procedures will be cortpleted after NRC approval of the plant-specific installation and the E0r technical guidelines.

10. Install additional CETs - Eight additional CETs will be installed during 1R8 which is currently scheduled for April through June 1988.

11. Implement ICC Technical Specifications - Technical Specifications covering the Limiting Conditions for Operation and the Surveillance Requirements for ICC instrumentation will be submitted following 1R8.

ATTACHMENT 1 (Cont'd)

. ANO-1 ICC MILESTONE SCHEDULE

SUMMARY

MILESTONE DUE DATE*

l

I

Submit Final Design Description l 7/4/86

{

Submit E0P technical guidelines l 7/4/86 i

, Complett: installation of ICC instrumentation l 1R7*

i Turn on system for operator training l 1R7*

l Complete ICC instrumentation functional l

testing and calibration l 90 days after 1R7*

i ,

Submit Implementation Letter l 180 days after 1R7*

l Approve plant-specific installation l Based on NRC schedules.

and E0P technical guidelines l Prepare revisions to plant operating l After NRC approval of procedures and emergency procedures l plant-specific installation

and complete procedure walk-through land E0P technical guidelines  ;

i l After procedure revisions

. Implement modified operating procedures l and procedure walk-through

and emergency procedures l are completed l Install additional CETs l 1R8**

Implement ICC Technical Specifications l Following 1R8**

I l

1R7 is currently scheduled for August'22 through November 1, 1986.

1R8 is currently scheduled for April through June 1988.

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